High resolution biostratigraphy of the Tournaisian-Visean boundary interval in the North Staffordshire Basin and correlation with the South Wales-Mendip Shelf

A study of three carbonate sections in the North Staffordshire Basin and two in the South Wales-Mendip Shelf yielded so far the richest foraminiferal associations at the Tournaisian-Visean boundary in Western Europe enabling a very good correlation with the stratotype area in South China. The biostratigraphic study was refined by sedimentological and gamma-spectrometrical data in order to define and calibrate the high resolution biostratigraphy across the boundary interval. The study illustrates the cryptic entry of the stratigraphically important species of the Chadian index genus Eoparastaffella which is abundant in photozoan facies. Across the Tournaisian-Visean boundary, changes in the character of the foraminiferal associations reflect the gradual change from heterozoan dominated late Tournaisian ramps to Visean photozoan dominated platforms. The combined application of biostratigraphic and sedimentological methods and gamma ray manifestation of the mid Avonian sequence boundaries have proved useful in the identification of the Tournaisian-Visean boundary in Carboniferous successions on either side of the Wales-Brabant Massif and has widespread applicability for successions of a similar age across Western Europe.